PC Assembling
For Assembling we need following necessary components
1. Motherboard
2. Processor
3. RAM
4. Hard Drive
5. CD/DVD Drive
6. Monitor
7. Keyboard
8. Mouse
9. ATX Power supply With ATX Cabinet
10. IDE/SATA, Power Cables and Computer Toolkit with Screws
Assembling Steps
Step 1 : Prepare Your Workspace
Step 2 : Install the Motherboard
Step 3 : Install the Processor (CPU)
Step 4 : Install the CPU Heat Sink
Step 5 : Install the Memory modules (RAM Memory)
Step 6 : Place the Motherboard into the Case
Step 7 : Connect the Power supply
Step 8 : Install the Graphics / Video card
Step 9 : Connect the keyboard, Mouse, and Monitor
Step10: Install the Drives
Step11: Install the Add-in cards
Step12: Turn the Computer On
Step13: Install the Operating System
Step14: Update Drivers with help of Motherboard CD
Step15: Install Anti- virus Software and setup a Network
Connection or Internet
Connection
Step16: Install Other Softwares
OS Installation – Windows XP / 7 , Linux – Ubuntu 11.10
1. When we start the Installation of Windows with Linux
2. First we need to Install Windows then We can Install Linux in
Dual boot
Environment
3. While installing windows, in partitioning stage we should give
some capacity of
HDD space as a unallocated (Unpartitioned) space, in this space
only we can install
Linux OS Later.
4. While Installing Linux We can Make Partitions automatically or
Manually. While in
Manual Partitioning make sure swap, boot and root partitions.
5. For swap partition we can give 512MB to 1024 MB
6. For Boot partition we can give 200 MB to 300 MB
7. For root partition we can give remaining capacity of HDD
unallocated space.
8. While installation of Linux we should give password for root
(Administrator)
To improve the System Performance, For improving system performance
we should follow the following
1. We should save our personal files instead of C:\
2. If virus found, Install latest update of Anti- virus program
and System full scan can be
done in safe mode
3. If getting message like Virtual Memory low! Then increase the
virtual memory in
system
properties>advanced>performance>advanced>virtual memory>change
4. Un install unnecessary softwares in safe mode
5. Use cleanup tool (In drive properties) to remove unnecessary
file stored on the
computer
6. Use disk defragmentation (In drive properties) tool to repair
fragmented files that can
improve the performance of HDD.
7. To improve boot process modify msconfig>startup options
8. Improve or upgrade RAM capacity
9. Stop unnecessary services in start>run>services.msc
SMPS Problem
1. For AT Power Supply, with help of PG signal (Orange wire ) we
can check +5 V, if it
comes then AT Power Supply is good. No need to short any wire for
getting the
output voltages
2. For ATX Power Supply, with help of PG signal (Grey wire ) we
can check +3.3 V, if
it comes then ATX Power Supply is good. Need to short green and
Black wire for
getting the output voltages.
3. Also Check Power Supply Fan, if it is not rotating can affect
entire system.
NTLDR file missing
1. If NTLDR file missing means we can restore it with help of WIN
XP OS CD.
2. Boot with Win XP CD then select Repair option (1st Repair) in
Recovery Console
3. Then Provide Administrator Password
4. Then Copy NTLDR file from WIN XP CD to C:\
Eg. E:\i386>copy ntldr C:\
Here E:\ is CD DRIVE
Booting problems
1. First need to check HDD detection in BIOS Setup, if not means
check the HDD data cable and power cable and reset those cables again.
2. Then check any CD or DVD that not as a boot able respective
drives
3. Then use F8 Advanced options while OS startup or Boot.
4. Use F8 Options like Last Known Good Configurations, Safe Mode
and Enable VGA Mode for Video related Problems
5. Use safe mode for Virus Scan, System File Checker(sfc
/scannow), Role Back Driver, System Restore, Backup and Restore and Un
Installation of softwares
6. Use safe mode with networking for virus updates and file
transfer
Beep sounds
Can hear these error codes when your computer boots up
1 Short Beep => Normal Boot
2 Short Beeps => POST error
No Beeps => Speaker broken, turned off, Power Supply or
Motherboard
Non Stop Beep => Power Supply or Motherboard
Non-Stop short beeps => Power Supply, Motherboard or Keyboard
with something
stuck or something on top of it
1 Long Beep followed by 2 or 3 short beeps => Memory or Video
Card
Hard Disk problem
1. Check HDD detection in CMOS Settings (Auto Detect)
2. Check the Data Cable and Molex Power Connections (line up pin
one)
3. Verify Jumper Settings (Master & Slave) when two devices
uses a single Cable
4. If ATA/33 means (40 wires) and ATA/66 and higher means (80
wires)
5. SATA Hard Drives supports Hot Swappable
6. If boot sector problem means Boot with Windows XP OS CD then
Select 1st Repair
option then use the command “fixboot” and “fixmbr”
RAM upgrade
1. When we upgrade RAM for new one, we should check the existing
type of RAM and
frequency of that RAM based on that only can be Up graded.
2. Capacity can be differ but frequency should be same.
Front Panel issues
Check the Block Diagram sheet comes with Motherboard Box, Also
refer Motherboard
Manual to fix Front panel Issues
Restart issues
1. Computer restarts due to
overheating
Computer restarts due to over-heating when the processor fan goes
faulty.
Solution:
Check that the cooling fans on the processor is working properly
or not. So ensure that the fan is working fine and is clean. If not, then get
the fan replaced. Also check for the additional fans on your computer
casing/cabinet (if any).
2. Computer restarts due to
faulty RAM
Computer restarts abruptly if RAM goes faulty, or if you install
some in-compatible RAM or more than one RAM modules of different frequency or
type.
Solution:
Buy an identical RAM module as your existing module, or better
approach would be to sell off the existing one and buy two new of same type,
brand, capacity and frequency.
3. Computer restarts due to
faulty Hard-disk
Faulty hard disk is one of the most common reasons for abrupt
computer restart. Run a hard
disk scan to fix this issue. If there are bad-sectors on your
hard-disk, it’s the time to get it replaced.
4. Computer restarts due to
overheating up of hard-disk
If there is not proper ventilation around your computer, the hard
disk may also reach
temperatures where it starts to malfunction and computer restarts
in some of these cases. The
fix is to keep the computer at a ventilated place. Also installing
some cabinet fans also solve this problem to big extent.
5. Computer restarts on
attaching some external USB device
Remove all external USB devices and insert one by one, and see
which device is causing problem
6. Computer restarts due to
other hardware problem
Computer restart problem is also caused by faulty motherboard
sometimes,for example if desktops BIOS went corrupt, But the chances of
motherboard are relatively low, so if nothing else seems to help, get the
motherboard checked by hardware vendor or technician.
7. Some software causing
operating system crash causes computer restart
Sometimes software can also be the culprit behind the computer
restart. If you have
Recently installed any new application or game, and computer have
started to restart when using that application or game, you need to un-install
it to fix the issue.
LAN issues
PING
Ping is the most important troubleshooting command and checks the
connectivity with other computers.
IPCONFIG
It shows the IP address of the computer and it shows the DNS,
DHCP, Gateway addresses the network and subnet mask. At DOS prompt type ipconfig
and press Enter to see the IP address of your computer. In DOS prompt / all and
press Enter to display the detailed information.
NSLOOKUP
NSLOOKUP is a TCP / IP-based command and checks domain name
aliases, DNS records,
Information on the operating system by query the Internet domain
name server
HOST NAME
Hostname command shows you the name of the computer.
At DOS prompt hostname and press Enter
NETSTAT
NETSTAT utility shows statistical protocols and the current
established TCP / IP connections to the computer.
NBTSTAT
NBTSTAT helps to resolve the NetBIOS name resolution problems.
ARP
ARP displays and modifies IP Physical address translation table
that is used by the ARP protocols
TRACERT
Tracert command is used to determine the path of the remote
system. This tool also provides the number of hops and the IP address of each
hop.
For example, if you see how many hops (routers) are involved to
achieve, www.yahoo.com, and what the IP address of each hop is then to use the
following command.
At the command prompt, type tracert www.yahoo.com you a list of
all the hops and their IP
Addresses to see
Installation , Configuration , basic mail troubleshooting
To configure your Outlook Gmail account
1. Start Outlook: Tools -> Email Accounts>select to
"Add a new e-mail account" and click on Next.
2. Select POP3 for the Outlook email account >On the User
Information section, enter your Name and your Gmail email address.
3. On the Server Information
section, enter the Google Gmail servers: - Incoming mail server: pop.gmail.com
and Outgoing mail server: smtp.gmail.com
4. On the Logon Information
section, enter your Gmail User Name (which is the same as your Gmail email
address) and your Gmail password.
5. Tick the box "Remember
password" in order to make Outlook to store the Gmail password
6. Click on the "More
Settings" button and go to the "Advanced" window tab.
On the "Incoming server (POP3)" field, enter 995 and
mark the box "This server requires an encrypted connection (SSL)"; On
the "Outgoing server (SMTP)" field, enter 465 or 587 and mark the box
"This server requires an encrypted connection (SSL)".
7. When you are done setting up your Outlook Gmail advanced
settings, click on OK to return to the Outlook Gmail account window.
8. To verify your Outlook Gmail
setup, click on the "Test Account Settings" button.
9. This will make Outlook to
attempt to login to your Gmail account and to send & receive an Outlook
test email.
10. If the test will succeed, you
will notice the test email in your Outlook Inbox folder.
11. If the test fails, Outlook
will prompt you with the error messages - most likely, you didn't setup the
correct server settings or the Gmail password is wrong.
Difference between Microsoft outlook and Outlook Express .
Microsoft Outlook:
Files will be saved in .PST Format.
Have some Additional Features like Address Book, Contacts, and
Remainder etc...
Not a free product have to purchase it.
Outlook Express:
Files will be saved in .DBX Format.
Don’t have any additional features.
Free product that comes along with the OS Installation.
Procedure for Backup and Restore Mail in Outlook Express
Go to C:\Documents & Setting\User Profile\Application
Data\Local
Settings\Identities\Outlook Express & Copy the .DBX files and
Save it in another location
as a Backup. Copy the files from the location that was saved as a
Backup & Go to the same
path & Paste it.
Or Use File menu>Export and Import
Procedure for Backup and Restore Mail in Microsoft Outlook
Go to C:\Documents & Setting\User Profile\Application
Data\Local Settings\Microsoft
\Outlook & Copy the .PST files and Save it in another location
as a Backup..
Copy the files from the location that was saved as a Backup &
Go to the same path & Paste it.
Or Use File menu>Export and Import
To repair a PST Files?
Using scanpst.exe command
To set and remove Password for PST Files ?
1. Select Go | Folder List from the menu.
2. Click on the root item of the desired PST file with the right
mouse button.
3. If you want to protect only certain email folders with a
password, you can move them to
a newly created PST file and assign a password only for that file.
4. Select Properties for... from the menu.
5. Click Advanced....
6. Now click Change Password....
7. Enter the desired password under both New password: and Verify
password:
8. If a password had already been set for the PST file, enter that
phrase under Old
password:
9. If you assign a password to a previously unprotected PST file,
leave the Old password:
field blank.
10. To remove the password from a PST file, enter it under Old
password: and leave both
New password: and Verify password: blank.
11. Click OK.
12. Click OK again.
13. Now click Cancel.
Assigning IP Address
Assigning IP can Done static (Manual), Dynamic, and Automatic
Manual or static>start>run>ncpa.cpl>Right
click Local area Connection>Properties>Select TCP/IP>
Properties>Type IP and Mask or Use Cmd>Type netsh interface ip set
address name="Local Area Connection" static 192.168.0.100
255.255.255.0 192.168.0.1 1
2. Dynamic IP Configuration can be Done With help of DHCP Server.
DHCP Server is used to assigns the IP address dynamically to the
DHCP Clients.
3. Automatic IP Configuration Can be done with help of APIPA, When
DHCP Server goes down or fails. APIPA range is 169.254.0.0 to 169.254.255.255
Installation, Configuration and Troubleshooting – printers
Installation local Printer
1. Go to Start Menu, Printers and Faxes.
2. Click the Add a printer > Next >Select local printer
3. Select a port from the drop-down menu, and click the Next
4. Select the manufacturer and printer, and click the Next. (You
can also use Have a
Disk option to add printer driver from a CD)
5. Specify a name for the printer and settings for using the
printer as a default printer, if you want to share the printer on the network.
Click the Next button.
6. Specify the settings for sharing the printer, and click the
Next button.
7. Specify the location and comment for the printer, and click the
Next button.
8. Specify whether or not to print a test page, and click the Next
button
9. Click the Finish button.
Installation of Network Printer
A network printer is a printer that is connected to a computer
network and can be accessed from many different computers.
1. Position your new printer near your switch or router. Plug the
Cat-5 cable that came with your printer into the network slot on the back of
your printer. Plug the other end into the back of your switch or router. Plug
in the power of your printer and turn it on
2. Put paper in the paper tray of the printer. Find the display
screen and use the buttons to find the option to print the printer's
configuration. Most network printers have a "Menu" button. From there
you can find the "Information" screen and choose "Print configuration."
Wait as the printer prints out a page and set the page aside for later
3. Turn on a computer >"Start" menu and either
"Printers and Faxes" or "Devices and Printers." Then select
"Add a Printer."
4. Choose "Network printer" and, when prompted for a
port, choose "Standard TCP/IP
Port."
5. Enter the IP address when prompted. You can find the printer's
IP address on the
configuration sheet you printed. If the wizard asks for a port
name, type "IP_," followed by the IP address.
6. Continue following the instructions on the wizard. If you are
asked for a network card type, choose "Generic Network Card." Insert
the CD that came with your printer when prompted to install your printer
drivers on the computer.
7. Type a name for your printer when prompted so you know what to
look for when connecting to the network from other computers. When asked about
sharing the printer, be sure to click the option to share it on the network
8. Complete the wizard by clicking "Finish." If you are
given the option to print a test page, do it to make sure your network printer
is set up properly
Service pack update, Anti-Virus installation and update
Service Pack
A service pack (in short SP) is a collection of updates, fixes
and/or enhancements to a software program delivered in the form of a single
installable package. Yes it should be installed in all the systems.
Virus - Vital Information
Resource under Siege It is an executable Program which Performs Malicious
activities in the system.
Antivirus
An Antivirus is software that protects the system from Virus
Attack.
Possible virus sources include e-mail attachments; Internet
downloads, and infected floppy Disks.
To prevent virus infections:
1. Use anti-virus software.
2. Perform regular updates to the virus software definition files
and scan engines. Verify updates have succeeded.
3. Perform regularly scheduled virus checks.
4. Configure software to check all files, not just program files.
5. Educate users on virus attacks, their consequences, and how to
prevent them.
6. Know where all software came from.
7. Do regular backups.
8. Develop reporting mechanisms to inform server administrators of
observed desktop infections and how these could impact the server environment
(such as deletions or corruption of files on public shares, hidden payload
files that might have been uploaded to servers, and so on).
Remote Desktop and Remote Assistance and knowledge on any third party
tool
1. Use Remote
Desktop (mstsc.exe) to access one computer from another
remotely. For example, you can use Remote Desktop to connect to your work
computer from home. You will have access to all of your programs, files, and
network resources, as if you were sitting in front of your computer at work.
While you are connected, the remote computer screen will appear to be blank to
anyone at the remote location who sees it.
2. Use Remote
Assistance (msra.exe) to give or receive
assistance remotely. For example, a friend or a technical support person can
access your computer to help you with a computer problem or show you how to do
something. You can help someone else the same way. In either case, both you and
the other person see the same computer screen. If you decide to share control
of your computer with your helper, you will both be able to control the mouse pointer.
Third Party Tools are Team Viewer, Real VNC Enterprise etc
Password Resetting (Admin / BIOS) - Administrator Password Resetting
in Windows
With Help of Third party Software
1. In WIN XP and WIN 7, we can reset a Administrator password with
help of ERD or Hiren Boot CD for Win XP and Win7.
2. Boot ERD then use LOCK SMITH Option for Resetting Administrator
Password.
3. Then remove ERD disk, Boot with Normal HDD, then Use Password
that you reset with ERD, Then Message will come “Password is Expired” then give
new password and confirm password then login.
With Help of Windows XP CD
1. Place your Windows XP CD in your cd-rom and start your computer
(it’s assumed here that
Your XP CD is bootable – as it should be – and that you have your
bios set to boot from CD)
2. Keep your eye on the screen messages for booting to your cd
Typically, it will be “Press any key to boot from cd”. Once you get in, the
first screen will indicate that Setup is inspecting your system and loading
files.
3. When you get to the Welcome to Setup screen, press ENTER to
Setup Windows now
4. The Licensing Agreement comes next – Press F8 to accept it.
5. The next screen is the Setup screen which gives you the option
to do a Repair.
6. It should read something like “If one of the following Windows
XP installations is damaged,
Setup can try to repair it”
7. Use the up and down arrow keys to select your XP installation
(if you only have one, it should already be selected) and press R to begin the
Repair process.
8. Let the Repair run. Setup will now check your disks and then
start copying files which can take several minutes.
9. Shortly after the Copying Files stage, you will be required to
reboot. (this will happen automatically – you will see a progress bar stating
“Your computer will reboot in 15 seconds”
10. During the reboot, do not make the mistake of “pressing any
key” to boot from the CD again! Setup will resume automatically with the
standard billboard screens and you will notice Installing Windows is
highlighted.
11. Keep your eye on the lower left hand side of the screen and
when you see the Installing
Devices progress bar, press SHIFT + F10. This is the security
hole! A command console will now open up giving you the potential for wide
access to your system.
12. At the prompt, type NUSRMGR.CPL and press Enter. You have just
gained graphical access to your User Accounts in the Control Panel.
13. Now simply pick the account you need to change and remove or
change your password as you prefer. If you want to log on without having to
enter your new password, you can type control userpasswords2 at the prompt and
choose to log on without being asked for password. After you’ve made your
changes close the windows, exit the command box and continue on with the Repair
(have your Product key handy).
14. Once the Repair is done, you will be able to log on with your
new password (or without a password if you chose not to use one or if you chose
not to be asked for a password). Your programs and personalized settings should
remain intact.
BIOS Password Reset
Remove CMOS Battery and Fix it again or changing the Jumper
Settings
Back up (Difference between each back up and its advantage), third party
tool for back up
Types of Backup in WinXP and Windows 2003
The Backup utility supports five methods of backing up data on
your computer or network.
Copy backup
A copy backup copies all selected files but does not mark each
file as having been backed up (in other words, the archive attribute is not
cleared). Copying is useful if you want to back up files between normal and
incremental backups because copying does not affect these other backup
operations.
Daily backup
A daily backup copies all selected files that have been modified
the day the daily backup is performed. The backed-up files are not marked as
having been backed up (in other words, the archive attribute is not cleared).
Differential backup
A differential backup copies files created or changed since the
last normal or incremental
backup. It does not mark files as having been backed up (in other
words, the archive attribute is not cleared). If you are performing a
combination of normal and differential backups, restoring files and folders
requires that you have the last normal as well as the last differential backup.
Incremental backup
An incremental backup backs up only those files created or changed
since the last normal or
Incremental backup. It marks files as having been backed up (in
other words, the archive attribute is cleared). If you use a combination of
normal and incremental backups, you will need to have the last normal backup
set as well as all incremental backup sets in order to restore your data.
Normal backup
Normal backup copies all selected files and marks each file as
having been backed up (in other words, the archive attribute is cleared). With
normal backups, you need only the most recent copy of the backup file or tape
to restore all of the files. You usually perform a normal backup the first time
you create a backup set.
Backing up your data using a combination of normal backups and
incremental backups requires the least amount of storage space and is the
quickest backup method. However, recovering files can be time-consuming and
difficult because the backup set can be stored on several disks or tapes.
Backing up your data using a combination of normal backups and
differential backups is more time-consuming, especially if your data changes
frequently, but it is easier to restore the data because the backup set is
usually stored on only a few disks or tapes
Third Party tools for
Backup
1. Acronis True Image
2. Norton Ghost
3. IBM Tivoli Storage Manager
4. Veritas Volume Manager
Knowledge on Firewalls
Firewall Restricts the System from Unwanted Traffic.
Firewalls, both hardware and or software-based, primarily protect
a network or central system from hacker intrusion from the Internet or other
public network. In addition, some firewalls also restrict LAN user access to
inappropriate websites. All networks with access to the Internet need a
firewall.
How a Firewall works
1. In the middle of the two networks sits a router.
2. An access control list is placed on the router which has a list
of IP addresses that can be allowed on to the network.
3. When you try to access the network, the router automatically
checks the list.
4. If your IP address is one of those on the list, you're allowed
in. If not, you sit outside
Limitations of Firewalls
1. Firewalls must be updated with a list of inappropriate banned
websites, as new sites appear very quickly.
2. Firewalls are not an effective protection against software
viruses. We recommend that all users install anti-virus software.
3. Often Firewalls are positioned between an Internet router and
the internal LAN, this result in a network bottleneck. Careful consideration
should be paid to where a firewall is placed. We recommend that the firewall is
installed between a switch and an Internet router.
4. Firewalls cannot protect against 'back doors', where a single
network user has installed a separate Internet connection. To prevent this,
companies should put an effective Internet access policy in place.
5. Equipped with the correct password, hackers can gain access to
your network in spite of a firewall. To solve this, all passwords should be
changed regularly
Knowledge on all protocols, OSI Layers (both approach), IP classes,
DNS, DHCP, AD, FTP and their port numbers
OSI Reference Model
It provides a framework for discussing network operations and
design.
There are 7 layers are there.
The processes at each layer of the OSI model
Layers PDU
Ø Application Data
Ø Presentation Data
Ø Session Data
Ø Transport Segments
Ø Network Packets/Datagrams
Ø Data Link Frames
Ø Physical Bits
IPv4 Classes
Unicast IP's
Class A => 0-126
Class B => 128-191
Class C => 192-223
Multicast IP
Class D => 224- 239
Reserved IP
Class E => 240-255
Private or Non-Routable IP range
Class A => 10.0.0.0-10.255.255.255
Class B => 172.16.0.0-172.31.255.255
Class C => 192.168.0.0-192.168.255.255
Loop back range => 127.0.0.0-127.255.255.255
Protocols
A set of rules for a particular type of communication.
Two types of Protocols
1. Connection Oriented 2. Connectionless Oriented
Connection Oriented
1. Follows the same path for data transfer
2. Acknowledgement
3. Reliable
e.g. TCP, SPX, AppleTalk datagram protocol
Connectionless Oriented
1. Follows the path where less traffic is found
2. No Acknowledgement
3. Non-Reliable
e.g. IP, IPX, UDP, AppleTalk protocol
Hypertext Transfer Protocol
Web pages are constructed according to a standard method called
Hypertext Mark-up Language
(HTML). An HTML page is transmitted over the Web in a standard way
and format known as
Hypertext Transfer Protocol (HTTP). This protocol uses TCP/IP to
manage the Web transmission.
A related protocol is Hypertext Transfer Protocol over Secure
Socket Layer (HTTPS), first introduced by Netscape. It provides for the
transmission in encrypted form to provide security for
sensitive data. A Web page using this protocol will have https: at the front of
its URL
Electronic Mail
Included in the email protocol are three distinct protocols.
SMTP (Simple Mail
Transfer Protocol), IMAP (Internet Message Access Protocol)
POP3 (Post Office
Protocol 3).
SMTP is a protocol
used for sending mail, while IMAP and
POP3 are used for receiving.
Almost all Internet service providers support all three protocols.
However the most popular setup for most providers is to use SMTP for sending
mail while using POP3 for receiving.
ICMP – Internet
Control Message Protocol
It is a Network Layer Internet protocol, which can report errors
and status information. We
can use the ping command to send ICMP echo request messages and
record the receipt of ICMP echo reply messages. With these messages, we can
detect network or host communication failures and troubleshoot common TCP/IP
connectivity problems.
ARP – Address
Resolution Protocol
The protocol that traces IP addresses to MAC addresses.
RARP – Reverse Address
Resolution Protocol
The protocol within the TCP/IP stack that maps MAC addresses to IP
addresses.
TFTP – Trivial File
Transfer Protocol
A stripped down version of FTP, easy to use and fast. TFTP has no
Directory browsing, no
Authentication and insecure it can only send and receive files.
FTP – File Transfer
Protocol
The TCP/IP protocol used for transmitting files between network
nodes. FTP allows access to both
Directories and files, manipulating directories, typing file
contents and copying files between hosts.
IPX
Internetwork Packet Exchange, layer 3 protocol used in Novell
Netware networks for transferring
Information from servers to workstations.
Difference between Switch & Hub
Switch:
Switches operate at Layer 2 Data Link Layer
Address Learning
Forward / Filter decision using MAC address
Loop Avoidance
Breakup collision domains
Switches create separate collision domains but a single broadcast
domain
Hub:
Hub operates at Layer 1 Physical Layer
No Filtering
No Addressing
Hub creates single collision domain and single broadcast domain
Make forwarding to all the ports when signal is arrived
Most Common Port Numbers
Protocol Port Number
Netstat 15
FTP 20, 21
TELNET 23
SMTP 25
WINS 42
DNS 53
BOOTP 67
DHCP 68
TFTP 69
HTTP 80
KERBEROS 88
POP3 110
NNTP 119
NETBIOS 139
SNMP 161
IMAP3 220
LDAP 389
SSL 443
RIP 520
MS SQL SERVER 1433
NFS 2049
X WINDOWS 6000
Knowledge on Nortan Ghost / Ghost image
Norton Ghost is a back- up and cloning solution for home and small
business users.
Norton Ghost lets you do the following:
1. Back up a computer: A full system back up of your computer.
2. Restore a computer if hardware or software failure occurs: Once
you have created a backup, you can quickly restore a computer to the last
backup copy.
3. Clone one partition or hard disk to another: Directly copy one
partition or hard disk to another, creating an exact copy of the original.
Virtual Machine installation and troubleshooting
Virtual Machine:
A self - contained operating environment that behaves as if it is
a separate Computer.
Virtual Machine Softwares:
MS Virtual PC, MS Virtual Server, VM Ware Workstation, Oracle
Virtual Box,
Hyper V in Windows Server 2008 Enterprise 64 bit Edition etc.
PC Top 5 Problems
Blue Screen of Death (BSoD)
Many people think of blue as a calming color; however, when it
comes up on your computer screen with a bunch of white text, it probably has
the opposite effect. The blue screen of death (BSoD or STOP Error) may appear
to be one of the scariest computer problems you'll come across. However, all
your computer may need is for you to reboot it. This STOP error appears on your
screen for a variety of reasons: failing hardware, damaged software, corrupt
DLL files, problems with drivers and more. The remedy for a blue screen of
death depends on the original problem. The screen provides you with codes that
can help you identify and fix your computer problems.
Missing DLL File
Dynamic-Link Library (DLL) files house information for your
operating system on how to perform certain functions. Occasionally, your
computer loses DLL files or something damages them. When your PC can't read the
particular DLL file, it doesn't know how to respond in certain situations. You
may have a missing or corrupt DLL file if you receive an error message every
time you perform a certain function, such as saving. If your computer problems
are stemming from missing and damaged DLL files, you can restore them by downloading
them back onto your PC.
Applications That Won't Install
If you're having trouble with an application not installing, it
may be because your computer doesn't have enough hard drive space. If this is
the case, you need to free up some space. This is one of the computer problems
that's, well, least problematic. You can free up some hard drive space by
getting rid of files and folders you don't need. These may be temporary files,
duplicate files or data for software you've uninstalled.
Applications Run Slowly
There are several reasons software might be running at turtle
speed. You may have computer problems that involve your operating system or an
application, your operating system might be missing updates or your computer
doesn't have enough hard drive space. If you don't have enough hard drive
space, you can scan, clean and optimize your hard drive.
Abnormal Applications Behaviour
Computer problems that involve applications acting strangely
oftentimes leave you wondering what has happened. Your application has been
working just fine, but now, seemingly without reason, it is doing something
strange. For instance, your Word document will no longer show the top margin of
your document. It still says it's there, and when you print it, there's not a
problem. You just can't see it on your monitor. If this is happening, you may
want to restart your computer. Conducting an internet search for the type of
problem you're experiencing or consulting your user manual may help you as
well.
Note
